Quantitative changes in the number of the mast cells in experimental inflammation produced by croton oil in rats.

The alterations of the mast cell number have been studied in experimental inflammation produced by croton oil in rats. The number of the mast cells was counted in the subcutaneous tissue and in the muscle layer round the granulomata. The results were evaluated statistically. The quantity of the mast cells showed an early tendency to increase which was statistically significant by the end of the 3rd day. The peak of the increase was found on the 11 day experiment. Later the number of the mast cells decreased slowly, however, it was still raised at 28 days. The behaviour of the mast cell number seems to support the secondary role of the mast cells in the inflammation.